Talebi Razieh, Nahal Arashmid, Bashouti Muhammad Y, Christiansen Silke H
Opt Express. 2014 Dec 15;22(25):30669-82. doi: 10.1364/OE.22.030669.
Irradiation of photosensitive thin films results in the nanostructures formation in the interaction area. Here, we investigate how the formation of nanostructures in photosensitive waveguide AgCl thin films, doped by Ag nanoparticles, can be customized by tuning the wavelength of the incident beam. We found, silver nanoparticles are pushed towards the interference pattern minima created by the interference of the incident beam with the excited TE-modes of the AgCl-Ag waveguide. The interference pattern determines the grating constant of the resulting spontaneous periodic nanostructures. Also, our studies indicate a strong dependence of the shape and size distribution of the formed Ag nano-coalescences on the wavelength of the incident beam. It also influences on the surface coverage of the sample by the formed silver nanoparticles and on period of the self-organized nano-gratings. It is found, exposure time and intensity of the incident light are the most determinant parameters for the quality and finesse of our nanostructures. More intense incident light with shorter exposure time generates more regular nanostructures with smaller nano-coalescences and, produces gratings with higher diffraction efficiency. At constant intensity longer exposure time produces more complete nanostructures because of optical positive feedback. We observed exposure with longer wavelength produces finer gratings.
对光敏薄膜进行辐照会导致相互作用区域形成纳米结构。在此，我们研究了如何通过调节入射光束的波长来定制掺杂有银纳米颗粒的光敏波导AgCl薄膜中纳米结构的形成。我们发现，银纳米颗粒被推向由入射光束与AgCl - Ag波导的激发TE模式干涉所产生的干涉图案最小值处。干涉图案决定了所形成的自发周期性纳米结构的光栅常数。此外，我们的研究表明，所形成的银纳米聚结物的形状和尺寸分布强烈依赖于入射光束的波长。它还会影响样品表面被形成的银纳米颗粒的覆盖程度以及自组织纳米光栅的周期。研究发现，曝光时间和入射光强度是影响我们纳米结构质量和精细度的最关键参数。强度更高且曝光时间更短的入射光会产生更规则的纳米结构，纳米聚结物更小，并产生具有更高衍射效率的光栅。在强度恒定的情况下，较长的曝光时间由于光学正反馈会产生更完整的纳米结构。我们观察到，波长较长的曝光会产生更精细的光栅。
